Mechanical stoker.



R. S. RILEY.

MECHANICAL STOKER.

APPLIOATIQN FILED FEB. 8. 1908.

l l 0%842, Patented Aug. 18, 1914.

2 SHEETS-SHEET 1.

R. S.'RILEY.

MECHANICAL STOKBR.

'APPLICATION FILED rma. s, 190B.

Patented Aug. 18, 1914.

Z SHEETS-SHEET Z.

UTE'D STATES PATENT OFFICE.

ROBERT S. RILEY, OF PROVIDENCE, RHODEISLAND.

MECHANICAL ST'OKER.

To all whom it may concern Be it known that I, Ronnirr S. RILEY, of Providence, in the county of .Providence and State of Rhode Island, have invented oerlain new and useful Improvements in Mechanical Stokers, of which the following is a specification. l

This invention relates to automatic stoking mechanisms by which coal is fed into the fire automatically, and has particular reference to that class of mechanical stokers operating to force the fuel from in front of and below the zone of burning fuel, and in which the incombustible residue of 'the fuel is fed by gravity to dumping means at the rear of the furnace.

In the type of stoker to which this invention relates, the fuel is fed through one or more vertical passage-ways having mouths which are in clined downwardly7 from front to rear,A and on each side of and between which passage-ways are air-supplying con-l duits closed'by twyer plates arranged in series which direct the air across the pas sage-ways into the burning fuel.

The present -invention consists in an improvement in the construction of the twyer plates which prevents their outer ends from beinff separated from the ones below, and in a contrivance located at the front of the furnace for introducing air across the passageways in a longitudinal direction above the fuel. Thev object of thus admitting air over the fire from above the fuel passage is to give a greater control over the flue gases, especially in cases ofrhigh overl-ating accompanied by traces of carbon monoxid in the Hue gas. I-n such event, air admitted over the fire helps toward the complete combustion of the fuel and thorough oxidation of the gases evolved therefrom. A further object is to enable the pusher, when a reciprocating cylindrical pushing plungeris used to force the fuel through the passage, to be rotated during the retracting stroke thereof so as to equa-lizethe wear, free the same of bits,

of coal, and prevent scoring ofthe surface.

In the drawings I have shown my 1mprovements applied to a mechanlcal stoker Specification of Letters Patent.

Application filed Februaiy 8, 1908.

in which coal is fed from a hopper' in front of the furnace by means of a staggered arrangement of upper and lower pushers, through passages or conduits having vert cal walls and rearwardly-sloping mouths,

Patented Aug. 18, 1914. Serial No. 414,900.

section of such a stoker, showing my iinprovements applied thereto. Fig. 2 represents a fragmentary sectional view of a modifica-tion in the arrangement for admitting air over the fuel passage. Fig. 3 represents an enlarged cross-sectional view at the upper and forward end of the fuel passage on the line 3-3 of Fig. 7. Fig. 4 represents a partial plan view of the Stoker. Fiozrepresents a perspective view of one of the improved twyer plates. perspective view of a form of cap or bridge covering the fuel passage and constructed to emit air longitudinally over the same. Fig. 7 represents a longitudinal sectional view through one of the air conduits and twyer plateson the line 7-7 of Fig. 4.

The same reference characters indicate the same parts in all the figures.

In the drawings, 1 represents part of a` boiler of any desired type, 2 the front wall end of the passage, and fuel is Iforced intol the latter by an upper pusher or ram 5. This pusher reciprocates horizontally and forces the fuel through the passage toward the rear, where it falls behind a lower and rearward pusher 6. These pushers are rei ciprocated by a drive shaft 7 through a worm 8, worm-wheel 9, second worm` l0 on the shaft of said wheel, and a second Wormwheel l1 on a countershaft 12. This shaft has as many crank-pins 13 as there are fuel passages in the furnace, each pin being connected by a connecting rod 14 with the adja-' cent upper plunger. This connecting rod is a bell-crank lever pivoted at its angle to a wrist-pin 15 in the upper plunger and having a lower arm 16 connected by a link 17 with the vlower pusher. The latter is cylindrical and reciprocates in a cylindrical bearing 18 in which it is capable of turning. It has a variable stroke so as to govern the relative amounts of fuel forced into the upper and lower parts of the furnace, the length of this stroke being governed by the distance from th-end of the link 17 of a head 20 on Fig. 6 represents aV a shank 21:, This shank is adjustably at-r tached to the link 17 by a clamp 22, and has teeth 23 meshing with complemental teeth on the clamp so as to hold it securely in any adjustment. The connection between this actuating mechanism and the pusher is effected bya spool or cam 24 having spiral ribs or threads 25 entering correspondingly-shaped grooves in a ring 26 castv on the inside of the pusher. This spool cam is movable axially of the pusher, and has a flange 27 which engages the ring when moved inward and so moves the pusher with it. The shank 21 passes and is freely movable through the spool so that on the retraction of the actuating mechanism, the head 20 engages and moves the spool rearward. A lip 28 on this head coming into contact with the inner side of the ring 26 draws the pusher backward and prevents the spool and head being withdrawn. There are intermeshing teeth on the adjacent sides of the head' 28 and cam 24 which engage as soon as the head reaches the cam and locks the latter against turning before it is moved. Thereupon the cam being retracted by the head, is carried through .the ring 26 before engagement of the lip 28 with the ring is e'ected, and this causes a rotation of the pusher before or during its retractive movement so that it may be loosened and prevented from sticking in its guideway. Upon return of the actuator, the

` head 28 is :first released from the teeth of the I nace.

cam and the shank advanced through the same until the end of link 17 upon which is a shoulder strikes the cam and pushes it further into the pusher, allowing it to rotate until its Hange 27 abuts against the ring. The end of the link and the head Aconstitute abutments which strike the member 24 alternately and push it back and forth. Thereupon the pusher is bodily forced into the fuel passage.

@n each side of the fuel passage are airboxes or conduits 29 which open into a transverse airtrunk 30 at the bottom of the fur- These air conduits 'are open on their up er and rear side, these openings being beside the sloping mouth of the "passage, The ,termination of the walls 31 which divide the fuelpassages from the air boxes forms the mouth of the passage and the opening of the conduits. These open sides of the conduit are partially closedby twyer plates 32 arranged in series, one upon another, the lowermost being supported by the bottom plate 33 of the furnace. The sides of the twyer plates at the rear are convergent, tapering to a blunt rounded point at the end, and their wider ends are shaped to lit against the edges of the partition walls 31. The upper surface of each twyer plate is formed as a tongue 34 slightly entering the air conduit and positioning the plate. Thus each series of twyers follows the slope of the passage mouth and the air conduit. The u/pper surface of each twyer plate is plane, but the found that there 1s a tendency for the rear n ends of the plates to lift under the influence of the weight of the plates above them, and to separate from the surface of the'adjacent plate below, leaving openings through which the air may pass directly to the rear instead of in the direction desired, which is intended to be given by the transverse passages. To prevent this effect, T have made the improvement in the twyer plates which constitutes part of this invention. Each plate has on` its under side near the tip, a projection 37 extending below the plane of its under side, and offset at the end to form a hook 38, this odset hook extending toward the point of the plate. Correspondingly, in the upper surface of each plate, except the uppermost, is a socket 39 which comes beneath the projection 37 of the plate above it when the plates are in their proper relative position, the offset hook 38 projecting beneath the upper surface of the lower plate and locking the two together, as best shown in Fig. 7. By means of this hook, each plate is securely anchored to the plate below it, and the lower plate lto the bottom 33 of the furnace, so that separation at their rear ends is prevented. Tn addition, each plate has in its rearward part a stud 40 which enters a hole 41 in the plate below, and so assists in keeping the plates in alinement. This stud is of small width, and does not materially obstruct the channel in the plate.

Across the top or upper forward end of the passage is placed a cap 42. Thiscap has upper and lower walls 43 44 which are i separated and provide a chamber or passage between them. This chamber being connected with a source of air, and having an external orilice, makes the cap in eiect a twyer or air duct, which bridges the passage and is so arranged as to discharge a stream of air rearward longitudinally of the passage and above the same. This air being introduced directly above the fuel,'serves to complete the combustion of gases delivered from the furnace, which may not have been completely burned. Preferably the walls of the cap converge so'as to make of the orice a horizontal slit 45 approximately `other figures.` In Fig. Q, a pipe 46 leads from anindependent conduit (not shown) to the twyerJ while in the other figures, the twyer is sh-own as being expanded' at the vrear `sodas to overlap the air-boxes 2S), and

having' channels 4,7 48 opening into the airboxes through which the air is admitted. The caps'rest on plates 49 which cover the upper ends of the twyer boxes. The space between each of these plates and the upper most one ofthe twyers 32 is closed so as to prevent vescape of air, by a plug 50 of wire netting and asbestos ber. Under the action of the heat this plug becomes firm and impervious.`

I claim:`

1. A mechanical stoker having a passageway for directing fuel to the fire-space, upper and lower pushers to forcethe fuel into and through such passage-way, air-admit ting means at each side of the passage-way, meansl for rotating the lower pusher prior to or during its retracting movement, and a cap bridging the passage-Way having -provisions for forcing air over the mass of fuel therein, above the top thereof.

2. A mechanical stoker having a passage or channel to direct fuel rearwardly from a supply outside of the furnace to the fire space r zone of burning fuel, pushing means for forcing the fuel through such passage or channel, air conduits formed on each side of the passage having longitudinal openings parallel with the mouth of the passage;

vchanneled twyer plates in continuous series covering the openings 'of Athe air conduits, and having hooks by which they are interlocked with one another and prevented from4 being lifted at theirinner ends by the weight of the superimposed twyers y 3. A mechanical stoker having a passage or channel to lead fuel rearwardly from a supply outside of the furnace to the firespace or zone of burning fuel, pushing means for forcing the fuel through such passagevor channel, air conduits provided on each'side of the passage having longitudinal openings parallel with the mouth of lthe passage; channeled twyer plates in continuous series covering the openings of the air conduits, each plate having a socket in one of its surfaces and a hookl projecting from its"oppositesurface entering the socket of, and interlocking with, the next adjacent plate.

4. A mechanical stoker having a passage or channel to leadl fuel rearwardly from a supply outside of the furnace to the firespace or zone of burning fuel, pushing means for forcing the fuel through such passage or channel, air conduits provided on each side of the passage having longitudinal inclined openings; channeled twyer plates in continuous series covering the openings of the air conduits, each having a portion projecting into, and held by the walls lof, the conduit, having also a socket in its upper side, and having a hook on the end most remote from the conduit entering and locking in the socket ,of the ladjacent plate, whereby the outer ends of the plates are prevented from separating.

5. In a Stoker havin fuel passages and an intermediate air con uit, twyer plates or entering and locking in the socket of theunder block, the Iupper block being also provided with lchannels in its under surface leading from the outlet of the conduit to discharge orifices in its sides. l

6. In a furnace the combination of superposed twyer blocks, each block being provided on opposite horizontal faces with a hook and a socket member, res ectively, with which the complemental soc (et and hook members of adjacent blocks coperate, whereby to prevent vertical displacement of the blocks.

7. In a furnace the combination of twyer blocks superposed `upon one another partially overlapping one another so as to form a slanting column, each block4 having up er and lower horizontal faces, the lower ace bein ing ook, and the upper face being provided with a socket member, the hook members of provided with a downwardly extendthe blocks being engaged with the socketv members of the adjacent blocks beneath, and the socket members engaged with the hook members of the blocks above.

8. A mechanical Stoker having a passage for guiding fuel from outside the furnace to the fire zone, air-supplying provisions on eachside of the passage arranged to discharge air into the burning fuel and ac ross the mouth of the passage; and a twyer br1dging the top of the passage and having a single elon ated shallow orifice of substantially equal width with the passage arranged to ydirect a broad current of air longitudinally over the Same above the top of the burning fuel.

9. A mechanical Stoker having a passage for guiding fuel from outside the furnace to the fire zone, pushing means for forcing the fuel through said passage, air supplying provisions on each side of the'passage arranged to discharge air4 into the burning fuel and across the mouth of the passage; a cap g horizontal direction to the air discharged through it, and terminating in a slit-like oriiice on'the furnace side'of the cap, whereby a broad stream of air is directed lengthwise of thepassage above the fuel in the same.

10. A mechanical stoker having a passage formed with an inclined outlet for guiding` fuel from outside the furnace to the fire zone, pushing means for forcing the fuel through said passage, air-supplying provisions on each side of the passage arranged to discharge air into the burning fuel and across the mouth of the passage; a cap having double walls to form an air passage converging to a shallow exit orifice, bridging the upper end of the passage above the highest ofv said air-supplying means, connected with the air conduits and arranged with its orifice directed longitudinally of the passage, so as to discharge a broad stream of air over the fuel. v

11, ln a furnace the combination of a series of air-outlet blocks resting one upon another and in communication with a source of air under pressure, each block having hook and socket members arranged respectively to engage an adjacent block on each side, whereby theblocks are secured.

12. A mechanical Stoker having a passageway for guiding fuel to the fire-space, upper and lower pushers to force the fuel into and through such passage way, air admitting provisions at each side of the passage-way; a lost-motion connection between the lower pusher and its actuating mechanism constructed and arranged to rotate said lower pusher a step at each retracting stroke thereof. l

13. A mechanical stoker having a passageway for directing fuel to the fire-space, upper A and lower pushers to force the fuel through such passage-way, air-admitting provisions at each side of the passage-way; a screw cam having a'threaded engagement withv the lower pusher and movable axially thereof, an actuator for the pusher and lostmotion connection between said cam and 'said actuator arranged to prevent rotation through such passage-way, air-admitting means at each .slde of the passage-way, a

pusher actuator, a connection between the lower pusher and said actuator consistin of a link having a shoulder, a head adjustzily secured to said link with provisions for Lioaaaa varying its distance from said shoulder, a member between said shoulder and head arranged to be engaged alternately .thereby and having a connection with said lower pusher such as to permit rotative and axial movements relatively thereto, and means associated with said head and member for preventing rotative movement of the latter when engaged by the head, whereby rotation of the pusher is e'ected.

15. A mechanical Stoker having a passageway for directing fuel to the fire-space, upper and lower pushers to force the fuel through such passage-way, air-admitting means at each side of the passage-way; actuating mechanism for the lower pusher, a lost-motionx connection between the lower pusher and said actuating mechanism constructed and arranged to rotate the pusher a step at each retracting stroke thereof, and a stop on the said actuating connection arranged to engage and move the plunger A axially after cessation of its rotating movement.

16. A mechanical stoker having a passageway for conducting fuel into the ire space, upper and lower pushers to force the fuel through such passage way, actuating means for reciprocating said pushers, and a lostmotion connection between said mechanism and one of said pushers constructed to rotate said pusher inthe course of its reciprocating travel.

17 A mechanical Stoker having a passageway for conducting fuel into the fire space, upper and lower pushers to force the fuel through such passage-way, actuating means '.for reciprocating said pushers, and a lostmotion connection between said mechanism and one of said pushers constructed to rotate said pusher in the course of its reciprocating travel in one direction, and permitting translative motion of the pusher without rotation in the opposite direction.

18. A mechanical Stoker having a passageway for conducting fuel into the fire space, upper and lower pushers to force the fuel through such passage-way, an actuator movable longitudinally of said lower pusher for reciprocating the same, and an intermediate member having an endwise twisting motion with respect to said lower pusher and arranged to be pushed back and forth by said actuator and held against rotation when forced in one direction, whereby the pusher is compelled to turn.

19. A mechanical Stoker having a passagei rotation upon occurrence of such longitudinal movement, and means whereby said actuator is caused to push said intermediate member back and forth and to prevent its rotation when thus moved in one direction.

20. A mechanical stoker having a passage- Way for conducting fuel into the fire space, upper and lower pushers to force the fuel through such passage-way, the lower pusher being rotatable about the line of its pushing travel, an actuator for said pusher, an intermediate member movable longitudinally with respect to the pusher and having a, spiral connection therewith such as to cause relative rotation upon occurrence of such longitudinal movement, and abutments on said actuator on each side of said intermediate member arranged to engage the same alternately, and one of said abutments having means to preventrotation of the said member.

21. Ina mechanical Stoker, a fuel feeding plunger, a guide for said plunger, and means for imparting rotative and reciprocatory movements to said plunger in said guide.

22. In a mechamcal Stoker, a reciprocatory fuel feeding plunger rotatable about an axis having the same direction as its line of reciprocation, and means for imparting rotative and reciprocatory movements to said plunger.

In testimony whereof I have aflixed my signature, 1n presence of two Witnesses.

ROBERT S. RILEY.

Witnesses:

ARTHUR H. BROWN, P. W. PEzzE'rrI. 

